class_docstr: Extract raw HTML from text.
  
  The raw HTML is stored in the [`htmlStash`][markdown.util.HtmlStash] of the
  [`Markdown`][markdown.Markdown] instance passed to `md` and the remaining text
  is stored in `cleandoc` as a list of strings.
code: def unknown_decl(self, data: str):
      end = "]]>" if data.startswith("CDATA[") else "]>"
      self.handle_empty_tag("<![{}{}".format(data, end), is_block=True)
  
imports: from __future__ import annotations
  import re
  import importlib.util
  import sys
  from typing import TYPE_CHECKING, Sequence
label_desc: Use image node_id 17 for calling the HTMLExtractor obj's underlying member method code with example usage: obj.unknown_decl(data) without return types